Free Internet Speed Test
SpeedTestAgent measures download, upload, and connection responsiveness in your browser. Run a free test with no app or account, then use the results to investigate slow speeds or lag.
Data usage warning: a test can exceed 1 GB on a fast connection. Use caution on metered plans.
How This Speed Test Works
SpeedTestAgent transfers data between your browser and Cloudflare's edge network, with our own server as a fallback if a transfer endpoint is unavailable. Results describe that route at that moment—not a guaranteed speed to every website. Your device, Wi-Fi, other traffic, and server routing can affect them.
The test starts with small HTTP requests to measure HTTP latency and HTTP jitter to the selected download endpoint — how long a round trip takes and how consistent that time is. It then uses parallel transfers to estimate download speed and upload speed. Along the way it checks loaded HTTP latency: the increase in round-trip time to that endpoint while transfers are running. The browser HTTP test does not measure IP packet loss.
Each transfer phase has a two-second warmup and an eight-second measurement window. The headline speed is server-acknowledged bytes transferred during that window divided by elapsed wall time. Data use increases with speed and can exceed 1 GB on fast connections; avoid testing on a limited data plan unless you are comfortable with that usage. See the measurement methodology and limitations.
How to Read Your Results
Download and upload describe observed capacity; endpoint-specific HTTP latency, HTTP jitter, and loaded HTTP latency add context about this tested path. They are not an overall verdict on your service or a prediction of application performance.
| Metric | What it measures | How to use it |
|---|---|---|
| Download (Mbps) | How quickly data reaches your device. | Compare with the needs of all simultaneous streams and downloads. More Mbps does not automatically reduce lag. |
| Upload (Mbps) | How quickly your device sends data. | Check your calling app's requirements and leave capacity for other callers and cloud backups. |
| HTTP latency (ms) | Average idle HTTP round-trip time to the selected download endpoint. | Lower is generally better for this path. A page, game, or call may use a different endpoint and route. |
| HTTP jitter (ms) | Average change between consecutive idle HTTP latency samples. | Lower means more consistent timing on this tested path. Repeat unusually variable results over Ethernet. |
| IP packet loss | Not measured by this browser HTTP test. | Use a suitable packet-level tool when direct IP packet-loss measurement is needed. |
| Loaded HTTP latency (ms) | The larger increase in median HTTP latency during download or upload over the idle baseline. | Less added delay is better on this tested path. The observation does not identify a cause or predict application performance. |
Grades describe this tool's observed measurements—not universal pass/fail standards. Repeat tests at different times, ideally over Ethernet, and compare the typical result with your plan. Our methodology lists the thresholds and calculation details.
Not Sure What Speed You Actually Need?
The right plan depends on simultaneous activities, not just the largest advertised download number. Answer a few questions about your household (streams, gaming, calls, work-from-home) and our calculator gives you concrete download, upload, and ping targets, with the per-activity math shown.
Find out what speed you needGetting Slower Speeds Than You Pay For?
Repeat the test over Ethernet with other downloads paused before blaming your provider. Compare wired and Wi-Fi results, check your router and Ethernet port capabilities, and temporarily disconnect a VPN if it is safe to do so. There is no universal percentage that proves an ISP is at fault. If wired results repeatedly miss your plan's expected speeds, save the results and ask your provider to investigate.
Our guides walk through each scenario in detail:
- Why Is My Internet Slow? 12 Causes to Check
- What Is a Good Mbps? Honest Numbers for 2026
- What Is Internet Jitter? Ping, Jitter & Packet Loss
- Wi-Fi vs Ethernet: Which Is Actually Faster in 2026?
- Is Your ISP Throttling You? How to Tell (and What to Do)
- How Internet Speed Tests Actually Work (and How to Get a More Useful Reading)
- How to Read Speed Test Results: Upload, Latency & Bufferbloat
Why We Built Another Speed Test
SpeedTestAgent combines throughput with responsiveness and loaded-latency checks, so you can investigate lag as well as slow downloads. See how we compare to Ookla and Fast.com.
A high download speed does not rule out latency or stability problems. SpeedTestAgent reports its observed metrics, applies published grade bands, and suggests troubleshooting steps. The test grade is not an overall verdict on your internet service. These are starting points, not proof of a particular fault. No account is required. See our privacy policy and methodology for the details, or the FAQ for common questions. Not sure what plan your household actually needs? Our speed calculator gives you a concrete download, upload, and latency target in under a minute.
Internet Speed Test Questions
How accurate is a browser speed test?
It estimates performance between this browser and the test endpoint at that moment. Device limits, Wi-Fi, background traffic, and routing affect results. Repeat tests under similar conditions rather than treating one number as your line's guaranteed capacity.
Should I test over Ethernet or Wi-Fi?
Use Ethernet to reduce wireless interference when checking your internet plan. Then test over Wi-Fi where you normally use your devices. If wired results are better, investigate wireless coverage and equipment before upgrading the plan.
Why is my speed lower than my plan?
Possible causes include Wi-Fi conditions, device or router limits, competing traffic, VPN overhead, congestion, and the route to the test server. A slow result alone does not prove throttling. Repeat wired tests at different times and compare them with your provider's stated expected speeds.
What speed do I need for streaming, gaming, or video calls?
It depends on how many activities run at once and each application's requirements. Streaming needs download capacity, calls need upload as well as download, and interactive gaming benefits from low, stable latency. Use our household calculator as a planning estimate, not a service guarantee.